Telephone system



April 8, 1947. J. H. voss EIAL TELEPHONE SYSTEM Filed 001:. 25, 1944 2Sheets-Sheet 1 INVEN-TORs. HERBERT E OBERGFELL EOEASED BY AMANDAOBERGFELL EXEOUTRIX 4mm u. voss ATTORNEY 2 Sheets-Sheet 2 I I I I l I lI I l I I p N m 8 S J INVENTORS.

HERBERT F OBERGFELL, DECEASED BY AMANDA OERGFELL,EXECUTRIX J. H. VOSS ETAL TELEPHONE SYSTEM Filed Oct. 23, 1944 April 8, 1947.

on n 5 Q l I I l I I I L 8m mun/r m n in mi 3m 7 I I III I l l J $1 N. 3N Twwm H5: 1| 9% u 228 mwoz E K an 9m Iii..- 3 d3 6 on JOHN H. voss BY lI ma I Patented Apr. 8, 1947 UNITED STATES PATENT OFFICE TELEPHONESYSTEM ware Application October 2-3, 1944, Serial No. 559,878

Claims. 1

The present invention relates in general to automatic telephone systemsand more particularly to improved circuit arrangement forinterconnecting a subscribers push-button calling device with amechanical dial repeater which is individual to the subscribers line.

The main object of the present invention is the provision of improvedimpulsing circuits for translating coded digits received from a codesending calling device to cause the operation of an impulse receivingand registering device to store and retransmit the translated digits.

Another feature of the invention relates to the circuit arrangementswhereby the impulse receiving and registering device, which isindividual to the Subscribers line, is arranged to receive and store thedigits transmitted by the calling subscriber while a finder switch ishunting for the calling line after whichthe stored digits aretransmitted to the automatic switch train. With this arrangement thecalling subscriber can immediately dial, or key, the called subscriber'snumber without waiting for the customary dial tone to inform thesubscriber that he may start dialling.

Another feature relates to the improved impulsing circuits whereby falseoperation of the impulse receiving and registering device is preventedwhen the subscriber initiates a call, answers a call or disconnects byreplacing the receiver.

Other features of the invention relate mainly to further detail circuitimprovements and will be apparent in the following description and inthe claims.

These circuit improvements, along with the push-button calling device,being claimed in a copending application Ser. No. 551,010, filed August24, 1944, and the mechanical dial repeater, being claimed in a copendingapplication Ser. No. 554,912, filed September 20, 1944, was designedprimarily for use by a subscriber who originates a large number ofoutgoing calls, such as a salesman or an order clerk. Such a subscribermay set up, or key, the digits of a called number without waiting forthe automatic telephone switches, such as finders, to find the callingline, and may proceed to call the desired called party as soon as thereceiver is removed from the cradle of the desk telephone. Thepush-button calling device is arranged to transmit loop and groundpulses over the subscribers line to a pair of line relays whichtranslate these incoming impulses into ground pulses to operate theimpulse receiving and registering device. Each line relay controls aseparate pulsing circuit and each such pulsing circuit extends to astepping magnet in the impulse receiving and registering device. Each ofthese stepping magnets singly, or in combination, control the steppingof a selecting arm; such.selecting arm being stepped one step for eachmagnet operation. On each loop impulse transmitted from the callingdevice, both line relays are operated to simultaneously control the twoseparate pulsing circuits thereby operating both stepping magnets tooperate the selecting arm a distance of two steps. A ground pulsetransmitted from the calling device causes only one of the line relaysto be operated while the other is maintained thereby only one of theseparate pulsing circuits is completed to operate only one of themagnets to step the selecting arm only one step. The selecting arm ismoved a number of steps corresponding to the translated digits to selectand displace a pin in the path of the sending arm in the impulsereceiver and registering device, or mechanical dial repeater. Thesuccessive digits are stored and marked by the displaced pins.

When the finder switch finds the calling line and connects theassociated selector switch to the calling line, a circuit is completedfor causing the impulse receiving and registering device to start thetransmission of outgoing impulses in accordance with the stored digits.A plurality of relays are operated to transmit the outgoing impulses andat the same time transmit a pulse to the sending magnet for eachoutgoing pulse. The sending magnet operates an arm step-by-step untilsuch arm encounters the first displaced pin at which time the relayoperations are stopped momentarily to operate a pin restoring magnetwhich restores the displaced pin. After the pin is restored the relaysagain transmit outgoing pulses and operate the sending magnet until thearm encounters the second displaced pin. T is same cycle of operationscontinues until all displaced pins are restored at which time the storeddigits would all be transmitted. The outgoing impulses operate theautomatic switches to complete the desired connection.

Referring now to the drawings:

Figures 1 and 2 diagrammatically show the circuits by means of which thepush button calling device and mechanical repeater control standardautomatic telephone switches to complete desired connections.

Referring now in detail to Figures 1 and 2, the push-button callingdevice diagrammatically Number 551.010 filed August 24, 1944. The same.

reference characters as used in the drawings showing the detailconstruction of the push. button calling device in the above-mentionedcopending application are alsoused'irrthe'circuit" diagram.

The substation circuit is. connected. by line.

conductors 2; and Eli! to individualcircuits. at. the main exchange.These circuits include a ring-control relay 2|5, a pair of line relays,a

repeating coil RC and other control relays; Some 1944. The same.reference characters'as applied r to the drawings showing the. detail.construction of. the. mechanical repeater. in the above-mentionedcopending application are also. applied to. the circuit diagram.

.Theconnector multiples. Conn, Mult. are connected to'the lineand testconductors 35B, 33! and 302- andare accessiblev to regular. standardconnector switches. in the main automatic.

exchange. I

Line: conductor. 300 isnormally connected to linev relay 3m in. the.usual manner while line conductor 3M is connected to an..open circuit atcontact 32'! instead. of the. usual ground connection for a. purposewhich. will be morefully describedhereinafter. The usual line cut-01frelay 32 3. isprovided and. is. operated on bothin'coming and outgoingcalls. The. circuits, terminate in finder bank contacts 33l to 334',inclusive, which are multiplied; and accessible to standard finderswitches, such as finder 34D. These. finders are of the.standardvertical and. rotary type of Strowger: finders having a.vertical motion. to find the bank level containingthe calling line and arotary motion to. find the calling, line in the bank level; A.distributor switch, such; as. distributor 350, is associated with the,group of finders. for controlling. the same to. find the .calling line.The finders and distributor switch. are. of the general type such. as.shown in the Saunders .Patent. 1,849,694 issued. March 15,1932. Aselectorv switch, such as selector 350, is tied tailto tail with eachfinder andhas access to other selectors or connector switches. in theusual manner dependent upon the capacity of. the automatic exchange. Theselector is. of. the well-known type of Strowger selector havingdirective vertical movement to select. a. group. of. trunks andautomatic rotary movement toselect anidletrunk from the selected group.Only line. relay 3.18 of selector 363 is shown for the purpose ofexplaining the control of impulse transmission start relay 240 whichoperates whenthe finderswitches through to the selector. to startretransmission of. the. digits storedi'n the mechanical di'al'repeater.

Having briefly describedthe. circuit layout a detail description willnow be given. The calling subscriber will. remove the telephonehandsetin- ,cluding. the. receiver. R and. transmitter T from the cradleand dial, or key, the digits of the called subscribers number. As iscustomary in multi-ofiice areas, the push-button calling device would beequipped with letters as well as digits on the push buttons and thecalling subscriber would key the. letters of the exchange and then thedigits of the called subscribers number in that exchange. Since thissubscribers line is equipped with an individual dial repeater, thesubscriber need: not wait for the customary dial tone but may startdialing immediately.

In response to the removal of the handset from the cradle,.cradlespring2 I! disconnects the ringer R, cradle spring" 2|6 closes a point in thetalking circuit, andcradle spring 2l5 completes a loop circuit throughthe substation circuit over the line conductors H8 and 2H, back contactsand armatures 2I-Iand 2l 2, through the left hand windings of repeatingcoil RC and through the windings of line relays 22!! and 230 to groundand battery for energizing line. relays 225 and 233. At front contact23! relay 230' completes a circuit for energizing slow-to-release relay260. At back contacts 2tl relay 263 disconnects ring control relay 2mand front contacts ZBI completes a circuit" for energizing line relay3"] as follows: from ground at contacts 242, contacts 225-, through theright hand winding of repeat.- ing coil RC and resistance R2, frontcontacts 26I, conductor 38!), contacts 321 and the winding of linerelay-313 to battery. At front contacts 262' relay 2'63 prepares acircuit for impulse transmission start relay 253 which circuit, however;is not completed until the finder switche through to the selector and atcontacts 233', 254', 265 and 251 prepares circuits utilized in theimpul'sing circuits to rotary stepping magnets RMZ and RMI. At contact26B're1ay 23B disconnects ground from conductor 308'.

Relay 3H], upon energizing, atcontacts 313 grounds the vertical bankcontact 334 and extends groundthrough the start resistance Rl to operatedistributor 350 which in turn starts an idle. finder in search. of thecalling line. At contacts 3H2", line relay 310, grounds conductor 302and the multiples of connector test termina'ls to busy this line. to theconnectors and at contacts 3| 1' marks the finder bank 333 and itsmultiples with calling potential through the windingofcut-off relay 323,

The calling subscriber need not wait for. the customary dial tone, whichis ordinarily transmitted to the calling line as soon as the finderswitches through. to the. selector. During the tim'e'the finder isearching for the calling line the calling subscriber may dial, or key,the digits of the called number. Assuming that the first digit dialed isan even number, digit 6 for example, the rocker arm and its insulatingplate 43 are operated, as described in the copending application Ser.No. 551,010, in. response. to the downward stroke of key 6 to separate.springs'lfl thereby disconnecting, ground from springs 13. Also inresponse to the downward stroke of key 3, the clutch arm 6.6 is rotatedofi normal thereby causing. the closure of shunt springs H which closesthe usual shuntaround the substation set and the clutch pawl slides overthe next three adjacent teeth on the ratchet wheel. When. key 6"restoresthe clutch returns to normal and rotates the impulse shaftandimpulse wheel 78 a distance of three teeth thereby actuating spring80 three times to separate contacts 82 three times. Contacts 82interrupt the, loop circuit extending toline relays. 220. and. 230 threetimestoicause three successive deenergizations and energlzations of bothline relays. The closure of contacts 13 during the transmission of thelast impulse is ineffective at this time because grounding sp 19 areopen.

Each time line relay 229 deenergizes a circuit is completed foroperating relay 295 as follows: from ground at back contacts 22I,contacts 261 and 283 and through the winding of relay 295 to battery.Relay 295 at contacts 296 prepares a circuit for relay 289 and atcontacts 291 completes a temporary locking circuit for itself. Thislocking circuit may be traced from ground at contacts 265, contact 291and 283 to relay 295.

Each time line relay 239 deenergizes a circuit is completed foroperating relay 299 as follows: from ground at back contacts 23I,contacts 294 and 214 and through the winding of relay 299 to battery.Relay 299 at contacts 29I prepares a circuit for relay 219 and atcontacts 292 completes a temporary locking circuit for itself. Thislocking circuit extends from ground at contacts 263 by way of contacts292 and 214 to the winding of relay 299. At front contacts 23I linerelay 239 temporarily opened the circuit to slow-to-release relay 269but this relay, due to its slow-torelease characteristics, maintains itsarmature attracted during the impulsing period.

When the loop circuit is closed at contacts 82 line relays 229 and 23Ireenergize. Relay 229 at front contacts 22I completes a circuit forenergizing pulse relay 289 by way of contacts 296 and relay 239 at frontcontacts 23I again completes the circuit to relay 269 before it couldfall away as well as completing a circuit for operating pulse relay 219by way of contacts 29L Relay 289, upon energizing, at contacts 28Igrounds conductor 394 to energize sloW-to-release relay 284 and rotarystepping magnet RMI. At contacts 282 relay 289 completes a temporarylocking circuit for itself from grounded contacts 265 by way of contacts282 and 296. At contacts 283 relay 289 opens the locking circuit torelay 295. Relay 219, upon energizing, at contacts 21I grounds conductor393 to energize rotary stepping magnet RM2. At contacts 213 relay 219completes a temporary locking circuit for itself from grounded contacts263 by way of contacts 213 and 29L At contacts 214 relay 219 opens thelocking circuit to relay 290. Rotary magnets RMI and RM2 in energizingposition their pawls preparatory to stepping the pin setting arm I59 onthe selecting member of the mechanical dial repeater.

Relays 219, 289, 299 and 295 are each arranged to restore theirarmatures within a predetermined time limit when their individuallocking circuits are opened in order to correctly pulse the rotarymagnets RMI and RM2. This timing being independent of the time ratio ofthe make and break connections at contacts 22I and 23 I.

Relays 299 and 295 deenergize when their locking circuits are opened bythe energization of relays 219 and 269. Relays 299 and 295 at contacts29I and 296 open the locking circuits of relays 219 and 289 to cause therelease of the latter relays. 1A1; contacts 21I and 28! relays 219 and289 disconnect ground from conductors 393 and 394 to release magnet RM2and RMI to simultaneously step both magnets. While the circuit torelay'294 is interrupted at contacts 282 this relay, due to its slowrelease characteristics,

maintains its armature attracted during each' ..s81i es of; incomingpulses. In response to the deenergization of both magnets RMI and RM2,the selecting mechanism and pin setting arm I59 are rotated from itslast occupied position a distance corresponding to two steps, or fromabove one pin, such as pin I69, past the next adjacent pin to above thenext subsequent pin. Therefore, in response to a single loop pulse, linerelays 229 and 239 cause magnets RMI and RM2 to move pin selecting armI59 two steps to select the second pin from its last occupied position.In the present example, since the key 6 has been actuated, three looppulses are transmitted to line relays 229 and 239 to control the relays219 and 289 in a manner similar to that above described, tosimultaneously operate both mag nets RMI and RM2 three times. Thesethree simultaneous operations of magnets RMI and RM2 step the pinsetting arm I59 six step from the last occupied position to a newposition above the sixth pin for the incoming digit 6 Series relay 284deenergizes shortly after the third, or last, release of pulse relay 219for this digit and at front contacts 286 opens the circuit to slow torelease relay 285 which maintains its armature attracted for a shortinterval. During this short interval a circuit may be traced forenergizing the pin setting magnet PSM as follows: from ground at backcontacts 286, contacts 281, conductor 395 and thru the winding of pinsetting magnet PSM to battery.

Magnet PSM momentarily operates its arma ture I21, the rod I99 and pinsetting arm I 59 to displace this selected sixth pin I99 to position itin the path of arm I99 of the sending member. Shortly after relay 294releases relay 285 also releases and opens the circuit to magnet PSMwhich restores. Pin setting arm I59, the rod I49 and armature I21 arerestored in response to the release of magnet PSM. It should bementioned that as soon as the pin setting arm I59 is moved from its lastoccupied position, or the position corresponding to the occupiedposition of arm I99, cam IN is rotated in unison with arm I59 andtherefore cam I1! permits contacts I93 and 194 to close thereby preparina circuit for controlling the retransmission of outgoing impulses.Transmission of these impulses, however, do not take place until theselector 369 is connected and ready to receive such impulses. All of theabove circuit operations have taken place in response to the actuationand release of key 9.

Assuming that the next, or second, digit dialed is an odd number, digit5 for example, the rocker arm and plate 49 are operated in response tothe downward stroke of key 5 to permit the closure of springs 19 therebyconnecting ground to contacts 13. The shunt springs 1! are again closedduring the time the clutch is off normal and the impulse shaft andimpulse Wheel 18 are rotated a distance corresponding to three steps, orthree cams of the impulse wheel 18, when key 5 restores. The impulsewheel 18 transmits two loop impulses and a ground pulse in this casebecause springs 19 are closed and are therefore effective when springs13 close during the last impulse to change the last transmitted impulsefrom a loop to a ground impulse. Arm 11 is operated on the returnoperation of the clutch to close springs 13 during transmission of thelast impulse in each series. During the transmission of the last pulsefor each odd digit a circuit may be traced for maintaining line relay239 energized while line relay 229 deenergizes. This circuit may betraced as follows: from ground at contacts 19, closed on all odd digits,contacts 13 closed on only the last pulse of each series, springs 89 and8|, shunt springs 1i, conductor 2l8', back contacts 2| I,upperzleit-hand winding of repeat coil RC and through the winding ofline relay 23% to battery. Therefore, line relay 220 deenergizes threetimes and line relay 233 deenergizes only twice whenever the number 5digit key is actuated and released. Rotary magnet RMI is thereforeoperated. and. released three times while rotary magnet RMZE' is.operated, and released two times thereby stepping pin setting arm I53equivalent to five steps to select another pin in the manner similar tothat previously described.

Relays 284 and 235 again operate, after transmission of the last pulsefor digit 5, to momentaril'y operate the pin setting magnet PSM which inturn operates the pin setting arm I51! to displace the last selected pinI31! into the path of arm 1'93.

Subsequent digits are transmitted and registered in the mechanical dialrepeater in the same manner as above described, it being remembered thatloop impulses are transmitted for each even numbered digits and thatboth loop and a ground pulse are: transmitted for each odd digit. Forexample,v five loop impulses are transmitted from the calling device toline relays 22B and 230 for the digit 0, the line relays translatingthese five impulses into ten pulses to magnets RM l and RMZ, five toeach magnet, for causing the mechanica-l repeater to take ten steps toselect and operate the tenth pin. For the digit 9 four loop pulses,followed by a ground pulse, are transmitted fromthe calling device toline relays 223 and 238 to operate rotary magnets RM! and RM2 In thiscase magnet RM! is operated five times and; magnet RM'Z four timesmaking a total of nine steps taken by the repeater to select the ninthpin. For the digit 1 only a single ground pulse is sentv and line rela223 alone transmits asingle pulse to magnet RMI. to step the repeaterone step.

For the digit 2 only a single loo-p pulse is transmitted from thecalling device and both line relays 223 and 23!] transmit a pulse toeach of the magnets RM l and RM2 to cause the repeater to take twosteps; The other digits are transmitted and registered in the repeaterin a manner apparent from the foregoing description.

Returning now to the operation of the distributor 350 and finder 343 andas a result of the operation of line relay 3H1, the finder wipers areoperated in a vertical direction in the well-known manner until verticalwiper 344 encounters the vertical bank contact 334 marked by ground atcontacts 313. As is well-known the finder wipers are. now rotated inthis level in search of the marking potential applied through thewinding of cut-ofi relay 32!! to bank contact 333. When finder testwiper 343 encounters this potential the switching relay (not shown) inthe finder switches the line and test leads through to selector 3'60 andalso completes the circuit for operating cut-off relay 323 fromconductor 311, wiper 343, bank contact 333, contacts. 31! and throughthe winding of relay 320 to battery. Cut-01f relay 320 at contacts 3'disconnects line relay 310 and at contacts 323 completes a lockingcircuit for itself independent of contacts 3!! from grounded conductor311. Line relay 3!!) deenergizes and at contacts 3i i opens the originalenergizing circuit of. relay 326 which is now locked up through its owncontacts. At contacts 3I3 relay 3!!) disconnects the marking ground fromvertical bank contact 334 andv start ground from the distributor 358. Atfront. contacts 3L2 relay 3lEl' disconnect's. direct groundfromconductor 302 and: the test conductor of the connector multiplesbut2atthe back contacts of armature 3I 2 relay 3! 0- sub-- stitutesground extending by way of conductor: 311, wiper 343, bank contact 333,contacts 323,. and back contact 3l2 for maintaining conductor 302- andthe test conductor of the connector multiples grounded therebymaintaining this linebusy to the connectors.

When the finder switches through to the selector a circuit is completedfor energizing line relay 310 as follows: from ground at contacts. 242,contacts 223', right hand windings of're peating coil RC and resistanceR2, front contacts: 23 i conductor 33E), finder bank contact 331, finderline wiper 34!, through contacts of the switching; relay (not shown) inthe finder and the upper:

'winding of line relay 31 E] to battery. Line relaytlc energizes andoperates the slow-to-release-re-- lay (not shown) in the selector tocause the latter relay to ground conductor 315 in the customary" manner.

As soon as thefinder finds the calling linean'd: switches through to theselector a circuit is com-- pleted for operating relay 240 whichinitiates the retransmission of the digits registered in the repeater.Retransmission of thefirst digit may take place after thefinder switchesthrough while. the repeater is still receiving subsequent digits fromthe calling device. The circuit for ener gizing relay 24c may be tracedas follows: from ground through the lower winding of selector line relay3'58, over the selector and finder line conductors to finder line wiper-34-2, bank contact. 332, conductor 33!, front. contacts 262, contacts2'43 and through the lower winding of relay 240: to battery. At contacts244 and 245 relay 240 completes a locking circuit for its lower winding.from grounded conductor 332 and opens its original energizing circuit atcontacts 246.

At contacts 2:31 and 243- completes a loop cir-- cuit as well asthepulsing circuit for selector line relay 319 in place of its originaenergizing cuit from contacts 242. This circuit extends'from' groundthrough the lower winding of line relay 313, wiper 342, bank contacts332, line conductor 331 front contacts 262, contacts 2M and 243, im--pulsing contacts 223, right-hand windings of re;- peat coil RC andresistance R2, front contacts 23!, line conductor 33!], bank contact33l, wiper 34!, over the line conductors in the finder and selectorthrough the upper winding of line: relay 310- to battery. At contacts241 relay 240 completes a circuit for relay 233 which is the first"relay of a chain of three relays for controlling the transmission ofoutgoing pulses from the repeater. The circuit for energizing relay 233may be traced as follows: from ground at contacts 223, contacts 241 and253, conductor 308 through the frame of the repeater to stop contactsI91 and I98, repeater cam contacts I93. and I94, spring wiper contactI92, conducting ring I95, conductor 309, contacts 221. and through thewinding of'relay 233 to battery.

Relay 233, upon energizing, at contacts232 completes an obvious circuitfor energizing relay 228 and at contacts 234 completes a locking circuitfor itself through contacts 221. At contacts 235 relay 233 completes anobvious circuit for slow-to-release relay 231 and also completes acircuit over conductor 3% for energizing sending magnet SM. Relay 231 atfront contacts 238 'completes a circuit for energizing slow-to-releaserelay 224 and at contacts. 233- maintains conductor 3%. grounded afterenergization ofrelay 224. Relay 223 at contacts 229 completes an obviouscircuit for energizing pulsing relay 225. Relay 224 at contacts 255prepares a point in the circuit for pin restoring magnet PRM and atcontacts 222 connects the Send Tone source through condenser CI to theupper talking conductor for the purpose of advising the callingsubscriber that the repeater is transmitting the registered digits. Thedisconnection of ground at contacts 223 is Without effect because groundat contacts 236 has been substituted therefore.

Pulsing relay 225, upon energizing, at pulsing contacts 226 opens thepreviously traced loop circuit extending to selector line relay 316 todeenergize line relay 310 for the first pulse. At contacts 227 relay 225opens the circuit for relay 233 whereupon relay 233 deenergizes to openthe circuit of relay 228 at contacts 232 and to open the circuit ofrelay 231 and sending magnet SM. Relay 231, due to its slow-to-releasecharacteristics, maintains its armature attracted during theretransmission of a series of pulses comprising a digit. Sending magnetSM deenergiz-es and steps the pin restoring arm I90 of the sendingmember one step over the next adjacent pin H39. Relay 228, upondeenergizing, at contacts 229 opens the circuit of pulsing relay 225which closes the loop circuit to selector relay 3'"! at contacts 226 andwhich closes the original energizing circuit of relay 233 at contacts22?. Relay 233 again operates thereby again operating relay 228 andsending magnet SM as well as recompleting the circuit for relay 231before it is restored. Relay 228 again operates pulsing relay 225 whichagain opens the loop circuit to line relay 313 to transmit another pulseat contacts 223 and again opens the circuit to relay 233 whichdeenergizes. Relay 233 again releases and opens the circuits to relay223 and sending magnet SM which operates restoring arm I99 of thesending member another step. Relays 225, 228 and 233 operate and releasewithin predetermined times according to their characteristics to causethe relay 225 to transmit loop pulses in accordance with the standardtime intervals normally required for the operation of the automaticswitches. Relays 228, 225, 233 and sending magnet SM operate in thismanner until sending magnet SM operates restoring arm I93 to the firstdisplaced pin I30 corresponding to the first registered digit. When thedisplaced pin is reached repeater stop spring I9! is disengaged fromspring I98 with the result that the circuit for relay 233 is not againcompleted during the transmission of impulses for this registered digit.The selector line relay 370 is deenergized for each pulse to step theselector Wipers in a vertical direction to select a group of trunks inthe level corresponding to the retransmitted digit in the well-knownmanner. Shortly after stop springs I97 and I38 are opened by the 1stdisplaced pin relay 237 deenergizes since the circuit to relay 233 wasopened by the stop springs. At contacts 236 relay 231 disconnects groundfrom conductor 338, at front contact 2% opens the circuit toslow-to-release relay'224 which maintains its armature operated for ashort period thereafter and at back contacts 238 momentarily completes acircuit through contacts 255 and over conductor 33'! for the pinrestoring magnet PRM.

Pin restoring magnet PRM is momentarily operated to operate its armatureI25 and pin restoring rod I19 thereby pivotally operating. pin restoringarm I 93 to restore the displacedpin to its normal position. Shortlythereafter slowto-release relay 224 deenergizcs and at contacts 255opens the circuit of pin restoring magnet PRM which restores itsarmature I25. The pin restoring rod [19 and pin restoring arm I arethereby restored to normal and stop springs I91 and I98 are permitted to'close. The selector 360 is automatically operated in its rotarymovement to select an idle trunk in the selected level during therelease time of relays 23'! and 224. When relay 224 closes contacts 223the original circuit previously traced for relay 233 is again closed toenergize relay 233. Relays 225, 228, 233, 231 and 223 operate in thesame manner as previously described, relay 225 to transmit loop pulsesat contacts 226 to operate subsequent automatic switches, relay 233 totransmit pulses to operate sending magnet SM until stop springs I9! andI98 are opened by the second displaced pin and re-. lays 231 and 223 tocontrol the operation and release of pin restoring magnet PRM as well asreinitiating the reenergization of relay 233 for a subsequent digit. Inthe same manner as just described, all of the registered digits, asdetermined by the displaced pins are retransmitted to operate theautomatic switches to complete the connection to the called line. Whenthe last .pulse of the last registered digit is transmitted spring I94engages cam I'II to separate springs I93 and I94 thereby preventingreenergization of relay 233. Springs I93 and I94 remain open until thepin selecting member and cam I'II are roe tated on a subsequent call.Shortly after the last retransmitted digit sending tone is disconnectedfrom the upper talking conductor thereby informing the callingsubscriber that the repeater has completed retransmission of. thedigits.

When the called subscriber answers the talk ing circuit iscompletedoverthe talking circuit comprising the heavy talking conductorsand repeating coil RC, the called subscriber being fed talking batteryfrom the battery feed relay in the connector in the usual manner whilethe'calling subscriber is fed talking battery. through the windings ofline relays 220 and 230.

After conversation and in response to the replacement of the handsets atboth calling and called substations the apparatus-and switch train isreleased. In response to the replacement of the handset at the callingsubstation line relays 220 and 230 deenergize andthe latter relayatfront contacts 23I opens the circuit of release re-. lay253. Atbackcontacts 23I and 221I relays 29!] and 295 again energize but theenergization of these relays is without efiect this time since the linerelays are not reenergized as during pulsing. Relay 260 deenergizesafter an interval and at contacts 263 and 265 open the locking cirecuitsof relays 290and 295 which deenergize. At contacts 268 re1ay;260grounds conductor 308 to automatically restore or spill out, anyregistered digits in the repeater in case a subscriber initiates andonly partly registers some of the calling partys digits and thenabandons the call. At contacts 26I and 262 relay 260 opens theloopcircuit across conductors 300 and Bill to release the automatic switchtrain in the. usual manner if not already released. I

In response to the'replacement of the handset on the cradle at eitherthe calling or called party's desk set ground is removed from thecontrol conductor 375 in the usual well-known manner. In response tothis removal of ground, cut-01f relay 320 and relay 240 deenergize. Allof the apparatus is now returned to normal and maybe used on subsequentcalls.

In case the calling subscriber should abandon-a call after one or moredigits have been registered in the repeater the line relays 220 and 230and the release relay 260 deenergize in the same manner aspreviouslydescribed. At contacts 2B] and 282 the loop circuit to theautomatic switch train is opened to release the switch train and thecircuit to relay 240 is opened to cause the latter relay to release. Atcontacts 26 8relay 251] grounds conductor 388 to cause the operation ofrelay 23.3 and the transmission of the registered digits stored in therepeater. The circuit for operating relay 233 extends from ground by wayof contacts 268, conductor 3 08, through the frame of the repeater tothe pin restoring arm I90, through stop springs I91 and I38, cam springsI93 and I94, wiper contact I92 and conducting ring 195, conductor 309,contacts 221 and through the winding of relay 233 to battery. scribedrelay 233 operates relay 228, relay 231 and sending magnet SM. Relay 228operates relay 225 which releases relay 233. Relay 225 opcrates itscontacts 226 as before but since the loop circuit is opened at contacts26I and 262 theoperation of contacts 226 is without effect and thestoredimpulses may be spilled out withoutoperating any switches. Stopsprings I91 and |38 are-controlled by the displaced pins correspondingto the stored digits to control the operation of relays 233, 2 31 and224 and pin ree storing magnet PRM in the same manner as previouslydescribed to restore all of the displaced pins. At the time the last pinis restored cam I'll opens cam springs !93 and I94 tostop furtheroperationsfof relay 233. The repeater is n resto-lodmto normal andniaybe used on sub-.- equentcalljs.

," Incorning calls arev completed. by way of the conn cto multipleso'nn; M w n nector'inotsho'wn) engages these bank contacts. h autbrn iconn ctor n the W own ma ner grounds conductor 301M181 the test bank 9mmo ergi e n c trofi e ay 3.29- At contacts-3y relay 32p disconnects linerelay 3H] from conductor 3110. The connector then canj s rin in ner tohe g e 7 1 1 0 1: ductor to energize ring r'elay 2|!) by way of ontacts26'! and condenser C2. Each time ring r ay Zllinergizes in response toringing current staid" relay at baclrcontactsfll and 2 12 dis nnects thesubscribers linefrom the repeati7 R an i i ifi "4 and 2 3 and tfrontfcontacts 2| l and 2l2 completes the ringing circuit byway ofconductor 21B, ringer R,,.

cradle springs 2 I 1, condenser C and conductor 2L9 for signalling thecalled subscriber. When the called"subscriber answers by removing thehandsef'from' its cradle a direct current bridge, including cradlesprings 2| 5, is closed across conduct0rs'"300 and130l to stop furtherapplications ofri'nging' current in the well-known manner. At contacts2l3 -rla y completes an obvious circuit forenergizing relay 2-50 whichat contacts 252 locks itself to grounded conductor 302} At contacts 251relay25ll. completes an energizing circuit through the upper winding ofrelay no there. byc'ausing'the energization of relay 242 which alsolocks to grounded conductor 392 at contacts :244and 245. At contacts 241andf'243 relay 240 prepares a point in the talkingcircuit. '7

"After ithecalled subscriber has removed' his handsetand. when ringrelay ZIO is deenergized line relays 220and 23U-areen'e'rgiz'ed over thesubscribers loop. At front'c'onta'c'ts'23l the an In the same manner aspreviously decuit is completed for energizing release relay 2.30 whichenergizes and completes the talking circuit at front contacts 25! and262. Although relays 290 and 295 energizeat this time, such energizationis without effect for the reasons previously mentioned. Line relays 220and 230-feed talking battery to the called subscriber while talkingbattery to the calling subscriber is fed. from the connector switch. Thetalk-ing circuit includes the heavy talking conductors, back contacts-2ll, 2&2, the windings of the repeat coil RC and front contacts 25! and262.

After conversation and in response to thereplacement of the handset,line relays 220 and 2-30 and release relay 260 deenergize. At frontcontacts 26! and 262 the loop circuit to the connector switch is openedto permit the release of the connector. When the connector releasesground is removed from conductor 302120 release relays 249, 258 and3281, The relays and; apparatus are now all restored to normal and'may'be used on subsequent calls What is claimed is:

1. In an automatic telephone system, a subscribers line, impulsereceiving and retransmitting means individual to said subscriber's lineand operative in response to a plurality of series of impulsestransmitted thereto by the calling subscriber to store said plurality ofseries or impulses, a plurality oifinders having access to said line,means responsive to the initiation of a call on said line forinitiating, the operation of one of said finders to hunt for the callingline, a selector switch associated with said one finder, meansresponsive to said one f nder finding the calling line forconnecting thecalling line tosaid selector switch in readiness to receive impulses,and means for initiating the retransmission of said stored series ofimpulses over said last men: tioned connection in response to thecondition:- ing of said selector switch to respond to said im-.- pulses.

2. In an automatic telephone system, asubscribers line, impulsereceiving and retransmit ting meansindividual to said subscribers lineand operative in response to a plurality of series of impulsestransmitted thereto bythe callin sub:

scriber to store said plurality of series of impulses, a plurality offinders havingaccess tosaid line, means responsive to theiniti ation ofa call on Said l f r n t at h rreration of one of said finders to huntfor thecalling line, ase lector switch associated with said one.finde1;; means responsive to said one finder finding the calling linefor connecting the calling linetogsaid selector switch in readiness toreceiveimm lses, means for initiating the. retransmission oi 5 id storedseries of impulses over said last rne'ntf ned connection in response tothe conditionlngjf said selector switch to respond .to said impulses,and means for transmitting a sending tonetothe calling subscriber duringthe retransmission of said stored pulses.

3. In an automatic telephone system, a sub scribers line, apushf-buttonlcalling devieeTi flia viduall to said line and operativefto.transrnit digits comprising coded pulses. circuit translating meansindividual to said line operated in response to the receipt of saidcoded. pulses for ,translat ing said coded pulses, into ground-pulsescorrespc-nding to the transmitted digitSQimpulsere-B ceiving andretransmitting means operated response to said. translated gr ound pul Vstoring saidtransmitted digits, ai pluirgiigy. g

finders having access to said line, means respon.

sive to the initiation of a call on said line for initiating theoperation of one of said finders to hunt for the calling line, aselector switch associated with said one finder, means responsive tosaid one finder finding the calling line for connecting the calling lineto said selector switch in readiness to receive impulses, and means forinitiating the retransmission of said stored digits over said lastmentioned connection in response to the conditioning of said selector torespond to impulse transmission.

4. In an automatic telephone system, a calling device for transmittingcoded digits comprising one or a plurality of loop pulses and a groundpulse corresponding to certain digits, a pair of line relays bothoperated in response to each transmitted loop pulse and only one of saidrelays operated in response to each transmitted ground pulse, circuitmeans controlled by each of said line relays for translating said codeddigits comprising 100p and ground pulses into pulses corresponding innumber to the actual value of the transmitted digit, and an impulsereceiving and retransmitting means operated in response to saidtranslated digits for storing said translated digits.

5. In an automatic telephone system, a calling device for transmittingcoded digits comprising one or a plurality of loop pulses, the number ofloop pulses in a coded digit being equal to onehalf the value of thedigit transmitted, a pair of line relays both operated in response toeach transmitted loop pulse, circuit means controlled by the operationsof said line relays for translating each loop pulse into a plurality ofpulses thereby translating the coded digits into pulses corresponding innumber to the actual value of the transmitted digit, and an impulsereceiving means operated by said translated pulses;

6. In an automatic telephone system, means for transmitting loop pulses,a pair ofline relays both operated in response to each transmitted looppulse, circuit means controlled by the operations of said line relaysfor translating each loop pulse into a plurality of pulses, and animpulse receiving means operated by each of said plurality of translatedpulses.

7. In an automatic telephone system, means for transmitting loop pulses,a pair of line relays both operated in response to each transmitted looppulse, circuit means controlled by the operations of said line relaysfor translating each loop pulse into a plurality of pulses, an impulsereceiving means having a plurality of stepping magnets, and means forsimultaneously operating said plurality of stepping magnets in responseto each said translated plurality of pulses to step said impulsereceiving means a plurality of steps to make a selection.

8. In an automatic telephone system, means for transmitting loop pulses,a pair of line relays both operated in response to each transmitted looppulse, circuit means controlled by the operations of said line relaysfor translating each loop pulse into a plurality of pulses, an impulsereceiving means having a' plurality of stepping magnets, a selectingdevice in said impulse receiving means, means for simultaneouslyoperating said plurality of stepping magnets in response to each saidtranslated plurality of pulses, and. a differential gear mechanismoperated by the simultaneous operation of said stepping magnets foroperating said selecting device a plurality of steps to make a selectionin accordance with the number of translated pulses received.

9. In a telephone system, a callingdevice'for transmitting pulses inaccordance with the digits in a called number, an impulse receiving andretransmitting device including a selecting arm operated step by step inresponse to the incoming pulses transmitted from said calling device tomake selections in certain positions in accordance with the transmitteddigits, 9, sending arm in said device normally having the same relativeposition as said selecting arm and adapted to follow said selecting arm,a stepping magnet for operating said sending arm over the same path assaid selecting arm, circuit means including a plurality of relays forcontrolling the transmission of outgoing pulses and for correspondinglyoperating said stepping magnet to operate said sending arm step by stepto the positions selected by said selecting arm, a circuit controlled bysaid sending arm at each said selected position for controlling saidcircuit means and relays to divide said outgoing pulses into groupscorresponding to the digits transmitted from said calling device, anautomatic switch train, and means for delaying the operation of saidcircuit means and said relays until such time as said automatic switchtrain is ready to respond to said outgoing pulses.

10. In a telephone, a subscribers line, a pair of line relaysterminating said subscribers line; acalling device at the subscriberssubstation for transmitting impulses comprising a pair of interruptersprings, a make-beiore-break spring for controlling said interruptersprings, a pair of grounding springs, and a pair of normally opensprings closed only during the transmission of the last impulse of eachseries, a loop pulsing circuit including both said line relays, saidinterrupter springs and both conductors of said line in series; agrounded pulsing circuit including said pair of grounding springs, saidpair of normally open springs, said make-before-break spring and one ofsaid interrupter springs, one of the line con ductors of said line, andone of said line relays in series; and subscriber controlled means foroperating said calling device to transmit loop and ground impulses oversaid impulsing circuits to operate said line relays whereby both saidline relays deenergize for each loop impulse and said one line relay ismaintained energized over said grounded pulsing circuit while the otherline relay deenergizes during each ground impulse.

11. In a telephone system, a subscriber's line, a pair of line relaysterminating said line, subscriber controlled means for operating saidline relays in response to the initiation of an outgoing call and inresponse to answering an incoming call and for restoring said linerelays in response the subscriber disconnecting from such calls,subscriber controlled means for restoring and reoperating said linerelays by transmitting impulses thereto, pulsing relays, meanscontrolled by the restorations and reoperations of said line relaysduring impulse transmission for operating said pulsing relays totransmit outgoing impulses, and means including said last means forpreventing the operation of said pulsing relays during the. operationsand restorations of said line relays for initiating outgoing calls, foranswering incoming calls and for disconnecting from such calls.

12. In a telephone system, a subscribers line, a pair of line relaysterminating said line, subscriber controlled means for operating saidline relays in response to the initiation of an outgoing call and inresponse to answering an incoming call and for restoring said linerelays in response to the subscriber disconnecting from such aersmoocalls, animpulsecalling device on said subscribersline for transmittingloop :andgroundpul'ses over said line to restore andreoperate said linerelays a plurality of times dependent'upon the number of loop and groundpulses transmitted,

a pair of pulse repeating relays for transmitting outgoing"impulses,means controlled by the restorations and reoperations of said linerelays during loop impulsing for operating both said pulsing relays totransmit a pair of outgoing impulses for each loop pulse and duringground impulsing for operating only one of said pulsing relays totransmit a single outgoing pulsefor each ground pulse, and meansincluding said last means for preventing operations of said pulserepeating relays during the operations andrestorations of said linerelays for initiating outgoing calls, for answering incoming calls andfor disconnecting for such calls.

13. In a telephone system, a subscribers line,

a; pair of line relays terminating said line, an impulse calling deviceon said line for transmitting operations of each of said pulse repeatingrelays, contacts on said one of said line relays for controlling one ofsaid separate circuits, and contacts on the other of said line relaysfor controlling the other of said separate circuits.

14. In a telephone system, a subscrib'ers line, a pair of line relaysterminating said line, an impulse calling device on said line fortransmitting" loop and ground pulses over said line to operate said linerelays, both said lines being operated inresponse to each loop pulse andonly one of said line relays being operated in response to each groundpulse, a pair of pulse repeating relays operative for transmittingoutgoing impulses, a separate circuit for controlling. the operations ofeach of said pulse repeating relays,

contacts on said one of said line relays for controlling one of saidseparate circuits, contacts on the other of said line relaysrforcontrolling the other of said separate circuits, and'an impulsereceivingand registering device controlledby the transmission of said outgoingimpulses in response to the operations of pulserepeating relays.

15. In a telephone system, a subscribers line, a calling device on saidsubscribers line for transmitting both loop and ground pulsescorrespond- 'ing. to the digitsin a called number inresponse' to thesubscriber initiating a call, an impulse re.- ceiving and registeringdeviceinidividual to said :subscribens line operated in responseto saidloop and ground pulses of said-transmitted digits for registering saiddigits, automatic switches,means including said receiving andregistering device for retrans'mitting said registered digits as loopimpulses only to-operate said automatic switches to complete the desiredconnection in accordance Withjsaid registered digits, and meansoperative theevent the-calling subscriber abandons the call for:operating said receiving. and registering device to eras saidregistrations without operating any of said automatic switches.

JOHN H. VOSS. AMANDA OBERGFELL; Execut'rz'x of the Estate of Herbert F.Obergfell,

deceased.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date Blessing Dec. 19, 1916 Cesareo Apr. 1,1941 Shephard Nov. 10, 1942 Dimond Dec. 1, 1942 Ostline -n Mar. 30, 1943Carpenter -1 Apr.- 1 2, 1 932 'Saville Apr. 18, 1939 Number

